The properties of transcriptional networks in late stage (branching morphogenesis) pancreatic bud precursor cells are inferred from the properties of well-studied networks in mouse models. In mice, committed but undifferentiated epithelial cells are organized into branching ductal structures. At a molecular level, expression of Pdx1, Nkx2.2, and Nkx6.1 is reduced while Hnf6 expression remains high. Hnf6 mediates the continued expression of Onecut3 and Hnf1 beta and epithelial cell proliferation. As expression of Ngn3 (corresponds to human NEUROG3) rises, endocrine differentiation of the epithelial cells begins (Servitja and Ferrer 2004; Chakrabarti and Mirmira 2003).